KR20150082426A - Led-based device with wide color gamut - Google Patents

Abstract

The present invention relates to a light source having a red light source with a spectral light distribution comprising a blue light source, a green light source, a first red light source comprising a first red fluorescent material configured to provide red light having a broadband spectral light distribution, And a second red light source comprising a second red phosphor material configured to provide light. In particular, the first red fluorescent material comprises (Mg, Ca, Sr) AlSiN ₃ : Eu and / or (Ba, Sr, Ca) ₂ Si _{5 - x} Al _x O _x N _{8 - x} : Eu, The red fluorescent material includes K ₂ SiF ₆ : Mn.

Description

(LED-BASED DEVICE WITH WIDE COLOR GAMUT)

The present invention relates to an illumination unit capable of generating light having a broad color gamut. The present invention also relates to an LCD display device comprising a lighting unit such as a backlighting unit.

Green luminescent materials for light emitting device (LED) applications are known in the art. International Patent Application No. WO / 2004/036962 discloses a light emitting structure capable of emitting primary light having a wavelength of, for example, less than 480 nm and a light emitting structure represented by the general formula (Sr _1-ab Ca _b Ba _c Mg _d Zn _e ) Si _x N _y O _z: Eu _a, to describe the LED including a phosphor screen including a phosphor (phosphor) of where 0.002 ≤ a ≤ 0.2, 0.0 ≤ b ≤ 0.25, 0.0 ≤ c ≤ 0.25, 0.0 ≤ d ≤ 0.25, 0.0? E? 0.25, 1.5? X? 2.5, 1.5? Y? 2.5 and 1.5 <z <2.5. International patent application WO / 2004/030109 also discloses an ultraviolet (UV) -blue excitable green (Eu) doped oxynitride host lattice consisting of a Eu-doped oxynitride host lattice with the general composition MSi ₂ O ₂ N ₂ Wherein M is at least one of the alkaline earth metals selected from the group (Ca, Sr, Ba).

Current phosphor-converted (pC-) LED solutions suffer from a lack of intensity in the red spectral range - this inhibits the production of warm white devices (CCT <5000K) (Lm / W) of such devices due to a limited eye sensitivity at wavelengths > 650 nm and also in a deep red spectral region, It seems to be damaging from having to use. The latter phosphors are band-emission materials based on activation by Eu (II) (i.e., bivalent europium). Using this activator, the spectral bandwidth represented by the full width half maximum (FWHM) of the emission spectrum is essentially limited to about 50 nm at the required emission wavelengths (maximum peak> 600 nm). Thus, for pc-LEDs, emissive materials having a narrow band in the red spectral region or having a line emission will be highly desirable because they will provide increased spectral efficiency for illumination purposes. In displays, such materials with saturated red color points lead to a wider color range when used, for example, in LEDs for LCD backlights.

It has been found that pc-LED fluorescent materials with narrow band or line emission are highly desirable. They appear to provide increased spectral efficiency and a significantly increased color gamut in the green and red spectral regions when applied to display backlight devices (improved color separation & saturation). However, even with the latest green and red phosphors such as rare earth doped YAG and Eu doped CaAlSiN ₃ , a limited color gamut can only be achieved.

Therefore, an aspect of the present invention is to provide an alternative lighting unit that is configured to utilize an alternative phosphor combination, which can provide a broad color gamut. It is also an aspect of the present invention to provide an alternative LCD display device that includes such a lighting unit that is configured as a backlight device (and that includes one or more color filters). Embodiments of the present invention also provide a combination of phosphors that can be applied in embodiments of the lighting unit.

In a first aspect, the invention provides a light emitting device comprising a first red light source comprising a first red fluorescent material configured to provide red light having a blue light source, a green light source, a broadband spectral light distribution, and a second red light source comprising a spectrum comprising one or more red emission lines There is provided a lighting unit comprising a second red light source comprising a second red phosphor material configured to provide red light with a light distribution.

In certain embodiments, the illumination unit comprises both, the narrow red emitting complex fluoride which is excited by the blue LED (e.g., K ₂ SiF _6: such as _{Mn (K, Rb) 2 SiF} 6: Mn) and Ln-doped (Ba, Sr, Ca, Mg) AlSiN ₃ : Eu, particularly (Sr, Ca, Mg) AlSiN ₃ : Eu) doped with at least one element selected from the group consisting of lanthanides, especially europium and / or cerium doped alkaline earth nitridesilicates Lt; RTI ID = 0.0 &gt; phosphorous material &lt; / RTI &gt; (Ba, Sr, Ca, Mg) AlSiN ₃ : Eu phosphors, especially Sr (Sr, Ca, Ca) , Mg) AlSiN _3: Eu can be obtained by adding a phosphor.

In another particular embodiment, a pc-pink LED is applied. The pC-pink LED element is a blue LED and a broad emission red fluorescent material (such as (Ba, Sr, Ca, Mg) AlSiN ₃ : Eu, especially (Sr, Ca, Mg) AlSiN ₃ : Eu) (Such as Mn doped K ₂ SiF ₆ ). The red phosphor mixture has a strong and broad absorption in the region of about 455 nm excitable by the blue LED. Simulating such phosphor layers with blue and green LEDs (centered at about 455 nm and 530 nm, respectively) reveals a significant improvement in the NTSC color gamut (≥ 80% and higher). The simulation is supported by the measured data of the prepared phosphor layers which very closely matches the simulation.

In a further aspect, the invention provides an LCD display device comprising a lighting unit as defined herein, configured as a backlight unit. Thanks to the large color gamut, a wide range of colors can be displayed by the LCD display device. As will be apparent to those of ordinary skill in the art, such an LCD display device may further include one or more color filters, particularly those filters disposed downstream of the backlight unit (but upstream of the display of the LCD display device).

In another aspect, the present invention relates to a process for the preparation of a zirconium-containing oxide from a group consisting of divalent europium containing oxynitrides, divalent europium containing thiogallates, trivalent cerium containing nitrides, trivalent cerium containing oxynitrides, (Ba, Sr, Ca, Mg) AlSiN ₃ : Eu and x is in the range of 0-4, such as 0 or 0.5-4, such as 2 or 3, A first red phosphor selected from the group consisting of (Ba, Sr, Ca) ₂ Si _{5 - x} Al _x O _x N _{8 - x} : Eu, and M ₂ AX ₆ is 4 doped with Mn-in which M is Li, Na, K, Rb, Cs, includes a monovalent cation (cation) selected from the group consisting of NH _4, and a is Si, Ti, Ge, Sn, and Zr, X is selected from the group consisting of F, Cl, Br and I, but at least F (especially substantially only &lt; RTI ID = And a second red fluorescent material selected from the group consisting of a monovalent anion comprising one or more anions, However, it should be noted that, in order to obtain the advantages of the present invention in an illumination unit or an LCD display device, other options than this phosphor combination can also be applied (see below).

The lighting unit of the present invention may be a lighting unit that is applied to general lighting, but may also be a lighting unit that is applied, for example, to a backlight. A non-limiting number of applications are shown below. It is noted that the term "illumination unit" may also be associated with a plurality of illumination units.

The illumination unit includes at least four light sources. As will be apparent to those of ordinary skill in the art, a lighting unit may only emit light when it is in operation (i.e., the lighting unit illuminates). The illumination unit will comprise at least one light source used as an excitation source. This may be, for example, a blue LED, or a UV LED, or a combination of both types of LEDs. The terms "blue LED" or "UV LED" refer to LEDs that are each configured to emit blue light or UV light during operation. As is known to those of ordinary skill in the art, the choice of excitation source (s) may depend on the type of fluorescent material. When the excitation source comprises UV LEDs, the illumination unit may further comprise a blue phosphor material configured to generate blue light upon excitation by the UV LED light source. It is noted that one or more other fluorescent materials may be configured to be excited directly by UV light and / or by blue light of a blue fluorescent material. It is noted that the terms "light source" and "LED" may also be associated with a plurality of light sources and LEDs, respectively. For example, when the green light source (see also below) comprises a fluorescent material, the blue LED may be configured to excite the green fluorescent material, the first red fluorescent material, and the second fluorescent material. For example, not only can pc-LEDs with green phosphors alone and pc-LEDs with only red phosphors (s) be selected, but also combinations of fluorescent materials can be selected on the LEDs ), Or remotely (i.e., at a non-zero distance) from the LED (s), for example as a coating on an emerging window or in a transmissive window. A pc-LED with a blue LED, with only the red fluorescent material (s) excitable by the blue LED, is also indicated herein as a pink LED. The term "blue fluorescent material" may also be associated with a plurality of blue fluorescent materials in embodiments. The term "light source" may in principle be associated with any light source known in the art, but may in particular refer to an LED-based light source as further represented herein as an LED. The following techniques will only cover LED-based light sources for convenience of understanding.

The light source is configured to provide UV and / or blue light (see above). In a preferred embodiment, the light emitting diode is configured to generate LED light having a blue component. In other words, the light source includes a blue LED. In yet another embodiment, the light emitting diode is configured to generate LED light with a UV component. In other words, the light source includes a UV LED. The UV light source is applied also when a blue or white light desired as the blue component, for example, a known substance BaMgAl ₁₀ O _17: Eu ²⁺ can is applied. However, other fluorescent materials capable of converting UV light to blue light can alternatively or additionally be applied. Preferably, the light source is a light source that emits at least light at a wavelength selected from a range of 200-490 nm during operation, and in particular at least a light source at a wavelength selected from a range of 400-490 nm, more specifically a range of 440-490 nm, It is a light source that emits light. This light can be partially used by the fluorescent substance (s) (see below). In certain embodiments, the light source comprises a solid state LED light source (e.g., LED or laser diode). The term "light source" may also relate to a plurality of light sources, such as 2-20 (solid state) LED light sources. Thus, the term LED can also refer to a plurality of LEDs. Thus, in a particular embodiment, the light source is configured to generate blue light.

 The term "white light" herein is known to those of ordinary skill in the art. This is especially true when the correlated color temperature (CCT) is between about 2000 and 20000 K, in particular between 2700 and 20000 K, in particular between about 2700 K and 6500 K for general illumination, Is in the range of about 7000 K to 20000 K and especially within about 15 SDCM (standard deviation of color matching) from BBL (black body locus), in particular about 10 SDCM from BBL, 0.0 &gt; SDCM &lt; / RTI &gt; from the BBL.

 In an embodiment, the light source may also provide light source light with a correlated color temperature (CCT) between about 5000 and 20000 K, for example, direct phosphor conversion LEDs (e.g., a phosphor thin layer to obtain 10000 K Blue light emitting diode). Thus, in a particular embodiment, the light source is configured to provide light source light with a correlated color temperature (CCT) in the range of 5000-20000 K, more specifically in the range of 6000-20000 K, for example in the range of 8000-20000 K . An advantage of a relatively high correlated color temperature may be that there may be a relatively large number of blue components in the light source.

Therefore, the lighting unit particularly includes a light source which may be at least one of a UV LED and a blue LED. An electron in combination with a blue fluorescent material that is configured to convert at least a portion of the UV (LED) light to blue light may provide a blue light source. Particularly, blue LEDs having a centroid emission particularly in the wavelength range (s) indicated above, especially 440-490 nm, are applied. Thus, in an embodiment, the blue light source comprises a blue light emitting diode (LED). The term "blue light source" may also relate to a plurality of blue light sources.

The blue light source may include one or more of (a) a UV LED in combination with a blue phosphor, and (b) a blue LED, and the green light source may be configured to convert at least a portion of the UV (LED) A UV LED in combination with a green phosphor, a blue LED in combination with a green phosphor (which is configured to convert at least a portion of the blue (LED) light to green light), and a green LED. As is apparent from the above, also combinations of two or more of these green light sources can be applied. Further, a green fluorescent material which converts at least a part of the blue light of the blue fluorescent material (when such a blue fluorescent material is applied) can be applied.

The term "green light source" may also relate to a plurality of green light sources. The term "blue fluorescent material" may also be associated with a plurality of green fluorescent materials in embodiments. In a particular embodiment, the green light source comprises a fluorescent material configured to convert at least a portion of the blue light of the blue light source and to convert the blue light into green light.

As shown above, the green light source may include a green phosphor that converts at least a portion of the light source light, such as a blue LED, to green light (during operation). In particular, the (green) fluorescent material may comprise one or more phosphors selected from the group consisting of trivalent cerium containing garnet and trivalent cerium containing oxynitrides. Thus, in an embodiment the green light source comprises a fluorescent material comprising M ₃ A ₅ O ₁₂ : Ce ^{3 +} , wherein M is selected from the group consisting of Sc, Y, Tb, Gd and Lu, A is Al And Ga. In particular, M comprises at least one of Y and Lu, wherein A comprises at least Al. These kinds of materials can give maximum efficiency. In a specific embodiment, the second red fluorescent material comprises at least two fluorescent materials of the M ₃ A ₅ O ₁₂ : Ce ³⁺ class, wherein M is selected from the group consisting of Y and Lu, A is selected from the group consisting of Al Wherein the Y: Lu ratio is different for at least two fluorescent materials. For example, one of them may be a pure Y group, such as Y ₃ Al ₅ O ₁₂ : Ce ^{3 +,} and the other may be (Y _0.5 Lu _0.5 ) ₃ Al ₅ O ₁₂ : Ce ³⁺ Y, and Lu based systems. Embodiments of garnet include in particular M ₃ A ₅ O ₁₂ garnets, where M comprises at least yttrium or lutetium and A comprises at least aluminum. Such garnet can be doped with a combination of cerium (Ce), praseodymium (Pr), or cerium and praseodymium; But can be doped especially with Ce. In particular, although A includes aluminum (Al), A may also partially include gallium (Ga) and / or scandium (Sc) and / or indium (In) In particular up to about 10% Al (i.e., the A ions are essentially composed of 90% or more of the mole% of Al and more than 10 or less mol% of one or more of Ga, Sc and In); A may in particular contain up to about 10% gallium. In yet another variation, A and O may be at least partially substituted with Si and N. The element M may in particular be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb) and lutetium (Lu). Also, Gd and / or Tb are present only up to about 20% of M in particular. In a particular embodiment, the garnet fluorescent material comprises (Y _1-x Lu _x ) ₃ B ₅ O ₁₂ : Ce, wherein x is equal to or greater than zero and equal to or less than one. The term ": Ce" or "Ce ^{3 +"} is the portion of the metal ion in the fluorescent material (that is, in the garnets: part of the "M" ions) indicates that this is substituted by Ce. For example, assuming (Y _{1- x} Lu _x ) ₃ Al ₅ O ₁₂ : Ce, a portion of Y and / or Lu is substituted with Ce. Such notation is known to the ordinarily skilled artisan. Ce will generally replace M by 10% or less; In general, the Ce concentration will be in the range of 0.1-4%, in particular in the range of 0.1-2% (relative to M). Assuming 1% Ce and 10% Y, the entire exact formula is _{(Y 0. 1 Lu 0. 89} Ce 0. 01) may be a ₃ Al ₅ O _12. Ce in garnets is substantially or only in a trivalent state, as is known to those of ordinary skill in the art.

In a particular embodiment, the green light source comprises an LED having a center emission wavelength in the range of 510 - 540 nm.

Red light sources generally always contain two (or more) different fluorescent materials. The first red fluorescent material provides broadband fluorescence at least in the red region portion of the spectrum when excited by light. The second red fluorescent material provides a spectrum with one or more lines upon excitation by light. Characteristic fluorescent species that generate line discharges are lanthanides (ff transitions such as Pr ^{3 +} , Sm ^{3 +} and Eu ³⁺ ), chromium ( ² E emission) and quadrivalent manganese (also ² E emission). In particular, the second red fluorescent material is based on quadrivalent manganese (MnIV).

Therefore, the red light source may be a UV LED in combination with a red fluorescent material (configured to convert at least a portion of the UV (LED) light into red light), whether it comprises a first red fluorescent material or a second fluorescent material, And a blue LED in combination with a red phosphor (configured to convert at least a portion of the blue (LED) light to red light). As is apparent from the above, combinations of two or more of these red light sources may also be applied. In addition, a red fluorescent material that converts at least a part of the blue light of the blue fluorescent material (when such a blue fluorescent material is applied) may be applied. Note that a single light source may be used to excite all fluorescent materials. However, it is contemplated that a subset of one or more light sources may be configured to provide red light with the first red fluorescent material and / or the second red fluorescent material, and another subset of the one or more light sources may be blue and / Green fluorescence) green light (see also above).

Examples of broadband emitters, narrowband emitters, and line emitters are described in, for example, G. Blasse and B.C. Grabmaier, Luminescent Materials, Springer-Verlag Berlin, Heidelberg 1994, and in particular in 1-6 and 10 (ISBN 3-540-58019-0 / ISBN 0-387-58019-0).

The term "(first or second) red light source" and similar terms may also be associated with a plurality of (first or second) red light sources, respectively. The term "first red fluorescent material" may also relate to a plurality of first red fluorescent materials in embodiments. Likewise, the term "second red fluorescent material" may also be associated with a plurality of second red fluorescent materials in embodiments.

In particular, broadband red emissive materials with a center wavelength greater than about 590 nm and a relatively wide bandwidth appear to be able to provide good results. Thus, in an embodiment, the first red light source is configured to provide red light having a broadband spectral light distribution with a FWHM of a center emission wavelength? 590 nm and? 70 nm, but especially? 130 nm. As is known in the art, broadband emitters are often systems with Stokes shifts. Here, the terms "center wavelength" and "full width half maximum" (FWHM) are specifically related to values that can be derived from the energy (such as W / nm) and from the emission spectrum at the wavelength scale. The term "central wavelength" is known in the art, which refers to a wavelength value at half the wavelength of which is at half the wavelength and half of the energy is at longer wavelengths; This value is expressed in nanometers (nm). This is the average of the spectra over the wavelength (Σλ * I _λ / (ΣI); normalized to the summed intensity over the emission band summed.) The center wavelength and FWHM, as always, It is determined at the room temperature of the material (especially 20 ° C).

The red luminescent phosphors with broad band emissions are especially divalent europium containing materials. Therefore, in a specific embodiment, the first red light source comprises the first red phosphor selected from the group consisting of divalent europium-containing sulfides, divalent europium-containing nitrides and divalent europium-containing oxynitrides. Therefore, in an embodiment, the first red fluorescent material is selected from the group consisting of a divalent europium-containing sulfide, a divalent europium-containing nitride, and a divalent europium-containing oxynitride. In particular, the first red fluorescent material (Ba, Sr, Ca, Mg ) AlSiN 3: Eu ( in particular (Sr, Ca, Mg) AlSiN 3: Eu) and _{(Ba, Sr, Ca) 2} Si 5 - x Al x O _x N _{8 - x} : Eu (having x indicated above). In these compounds, europium (Eu) is substantially or only divalent and displaces at least one of the indicated divalent cations.

Generally Eu will not be present in an amount exceeding 10% of the cations relative to the cation (s) it substitutes, especially in the range of about 0.5-10%, more particularly in the range of about 0.5-5% . The term ": Eu" or: The "Eu ^{2 +"} indicates that a part of the metal ion is substituted by Eu (in these examples Eu ^2+). For example, CaAlSiN _3: assuming 2% Eu in the Eu, the correct formula is _(.. Ca _{0 98 0 02} Eu) AlSiN may _3rd. Divalent europium will generally replace, for example, divalent cations such as the divalent alkaline earth metal cations, especially Mg, Ca, Sr, and Ba, more particularly Ca, Sr or Ba.

Further, the substance (Ba, Sr, Ca) ₂ Si _{5 - x} Al _x O _x N _{8 - x} : Eu (having the abovementioned x) is also represented by M ₂ Si _{5 -x} Al _x O _x N _{8- x} : Eu , Where M is at least one element selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); In particular, in an embodiment, M comprises Sr and / or Ba in this compound. Therefore, the term "(Ba, Sr, Ca)" and similar terms may indicate that at least one of Ba, Sr and Ca is present in the compound (at the M position (s)). In a further specific embodiment, M is, for example, Ba _{1 . 5} Sr _{0 . In} particular 50-100%, in particular 50-90% Ba and 50-0%, in particular 50-10% Sr of Sr, such as ₅ Si ₅ N ₈ : Eu (i.e. 75% Ba: 25% Sr) And / or Ba (without considering the presence of Eu). Here, Eu is introduced and at least one of Ba, Sr, and Ca is substituted.

Similarly, the material (Ba, Sr _, Ca, Mg) AlSiN ₃ Eu can also be expressed as MAlSiN ₃ Eu ₅ where M is composed of Ba, Sr _, Ca and Mg &Lt; / RTI &gt; In particular, M comprises in this compound calcium or strontium, or calcium and strontium, more particularly calcium. Here, Eu is introduced and at least part of M (i.e., at least one of Mg, Ba, Sr, and Ca) is substituted. Preferably, the first phosphor is (Ca, Sr, Mg) AlSiN ₃ in Embodiment includes a Eu: Eu that is, good CaAlSiN _3. In yet another embodiment, the first red fluorescent substance which can be combined with the former _{(Ca, Sr, Ba) 2} Si 5-x Al x O x N 8-x: Eu, preferably (Sr, Ba ) ₂ Si ₅ N ₈ : Eu. The term "(Ca, Sr, Ba)" indicates that the corresponding cation can be occupied by at least one of calcium, strontium or barium. It also indicates that the corresponding cation sites in such a material may be occupied by cations selected from the group consisting of calcium, strontium and barium. Thus, the material may include, for example, calcium and strontium, or strontium alone, and the like. In a similar way, this applies to other terms (with such cation (s)).

Thus, in embodiments, the first red fluorescent material M ₂ Si ₅ N _8: may further include a Eu ^{2 +,} wherein M is Ca, is selected from the group consisting of Sr and Ba, more specifically from M Is selected from the group consisting of Sr and Ba. In another embodiment, the first red fluorescent substance which can be combined with the former MAlSiN _3: may further include Eu ^2+, where M is selected from the group consisting of Mg, Ca, Sr, and Ba, More particularly, M is selected from the group consisting of Sr and Ca.

In addition, (second) red pre-emissive materials with a central wavelength greater than about 610 nm and a relatively narrow bandwidth, such as, for example, the quadrivalent manganese-containing systems mentioned above, may provide good results . In particular, the second red light source is configured to provide red light having a spectral light distribution comprising one or more red emission lines having a central emission wavelength ≥ 610 nm, and also having one or more red emission lines with an FWHM of ≤ 50 nm .

A specific example of such a second red fluorescent material has a type M ₂ AX ₆ doped with Mn ^{4 +} (i.e., at position A). In particular, the second red light source comprises the first red phosphor selected from the group consisting of M ₂ AX ₆ doped with tetravalent manganese wherein M is Li, Na, K, Rb, Cs, NH ₄ (K), wherein A comprises a tetravalent cation selected from the group consisting of Si, Ti, Ge, Sn, and Zr, In particular silicon (Si), wherein X comprises a monovalent anion selected from the group consisting of F, Cl, Br and I, but comprises at least F (and in particular substantially only F). In this regard, the phrase "include at least" refers specifically to embodiments that can include at least one of the specified species of paper marked species, but at least include species indicated as " including at least &quot;. By way of example, when M comprises at least K, it implies embodiments where the species or univalent cation M (or the lattice site (s) of M) comprises> 0% to 100% of K . Thus, for example, the following examples are included: (K _0.01 Rb _0.99 ) ₂ SiF ₆ : Mn, RbKSiF ₆ : Mn, and K ₂ SiF ₆ : Mn, In an embodiment, M comprises K and / or Rb (i.e., (Rb, K) ₂ SiF ₆ : Mn).

As known in the art, "M ₂ AX ₆ doped with Mn ^{4 +} " can also be denoted M ₂ AX ₆ : Mn ^{4 +} . Here, the term " Mn "or" Mn ^{4 +} "indicates that some of the tetravalent A ions are substituted by tetravalent Mn. The term "tetravalent manganese" refers to a Mn ^{+ 4.} This is a known fluorescent ion. In the formula shown above, a portion of the tetravalent cation A (e.g., Si) is replaced by manganese. Therefore, M ' _x M _{2 - 2x} AX ₆ doped with quadrivalent manganese can be represented as M' _x M _{2 - 2x} A _{1 - m} Mn _m X ₆ . The molar percentage of manganese, that is, the percentage by which this substitutes quaternary cations A will generally range from 0.1 to 15%, in particular from 1 to 12%, i.e. m is in the range from 0.001 to 0.15, in particular from 0.01 to 0.12.

A comprises a tetravalent cation, especially at least silicon. A may optionally further include at least one of titanium (Ti), germanium (Ge), tin (Sn), and zinc (Zn). Preferably, at least 80%, more preferably at least 90%, such as at least 95% of M is comprised of silicon. Thus, in certain embodiments, M ₂ AX ₆ Also A ₁ M _{2 m -mtgs- zr} Mn Ge Ti _{t s g} Sn Zr _zr may be described as X _6, wherein m is as indicated above, t, g, s, zr is are preferably each individually 0 &gt;, especially 0-0.1, more particularly 0-0.05, wherein t + g + s + zr is less than 1, especially less than 0.2, preferably 0-0.2, especially 0-0.1 , More particularly in the range of 0-0.05, and A is especially Si.

As indicated above, M is associated with monovalent cations, but specifically includes at least one of potassium and rubidium. The other one, which may be included in addition to the M by a cation may be selected from the group consisting of lithium (Li), sodium (Na), cesium (Cs), and ammonium (NH ₄ ^+). Preferably, at least 80%, more preferably at least 90%, for example 95% of M is comprised of at least one of potassium and rubidium. In a particular embodiment, M ₂ AX ₆ can also be described as (K _{1 -rlnc-nh} Rb _r Li ₁ Na _n Cs _c (NH ₄ ) _nh ) ₂ AX ₆ , where r is in the range 0-1 (And wherein the potassium rubidium ratio is preferably as indicated above), wherein l, n, c, and nh each independently preferably range from 0-0.2, especially 0-0.1, more particularly 0-0.05 Where l + n + c + nh is less than 1, in particular less than 0.2, preferably in the range of 0-0.2, especially 0-0.1, more particularly 0-0.05. Therefore, the present invention also provides (K _{1 -rlnc-nh} Rb _r Li ₁ Na _n Cs _c (NH ₄ ) _nh ) ₂ AX ₆ : Mn and similar narrow band fluorescent materials. A is herein specifically silicon.

As noted above, X is associated with a monovalent anion, but at least includes fluorine. Other monovalent anions that may optionally be present may be selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I). Preferably at least 80%, more preferably at least 90%, for example 95%, of X is composed of fluorine. Thus, in a particular embodiment, M ₂ AX ₆ may also be described as M ₂ A (F _1-cl-bi Cl _cl Br _b I _i ) ₆ , where cl, b, i are each individually preferably I is in the range 0-0.2, in particular 0-0.1, more particularly 0-0.05, and cl + b + i is less than 1, in particular not more than 0.2, preferably 0-0.2, in particular 0-0.1, Is in the range of 0-0.05.

Accordingly, M ₂ AX ₆ also _{(K-1 rlnc-nh} Rb _r Li _l Na Cs _{n c} (NH _{4) nh) 2} Si _{1-m mtgs-zr} Mn Ge Ti _{t s g} Sn Zr _zr (F _{1- cl-bi} cl _cl Br _b i _i) may be described as _6, the values for r, l, n, c, nh, m, t, g, s, zr, cl, b, i are shown in the display same. Thus, the present invention can also _{(K-1 rlnc-nh} Rb _r Li _l Na Cs _{n c} (NH _{4) nh) 2} Si _{1-m mtgs-zr} Mn Ge Ti _{t s g} Sn Zr _{zr (1-F cl- bi cl cl Br b i i)} 6: Mn and provides a similar narrow band fluorescent substance. However, in particular, the second red light source comprises the second red phosphor material including K ₂ SiF ₆ : Mn.

As manganese substitutes for some of the matrix lattice ions and has a particular function, it is also referred to as a "dopant" or "activator &quot;. Hexafluorosilicate is thus doped or activated with manganese (Mn ⁴⁺ ).

In addition to or in addition to the manganese-containing system, the second red light source may comprise the second red fluorescent material comprising a photoconversion nanoparticle material.

Nanoparticles such as quantum dots (QDs) have attracted great interest in lighting applications. They may serve, for example, as inorganic phosphors in converting blue light into other colors, and also have the advantage of a relatively narrow emission band and the advantage of a color that is adjustable by the size of the QDs, thereby achieving high-quality pure white light.

The quantum dots or fluorescent nanoparticles, which are referred to herein as photoconductor nanoparticles, can be, for example, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe selected from, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, the group consisting of CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe Lt; RTI ID = 0.0 &gt; II-VI &lt; / RTI &gt; compound semiconductor quantum dots. In another embodiment, the fluorescent nanoparticles may be doped with a dopant such as, for example, GaN, GaP, GaAs, AlN, AlP, AlAs, InN, InP, InAs, GaNP, GaNAs, GaPAs, AlNP, AlNAs, AlPAs, InNP, V compound semiconductor quantum dots selected from the group consisting of GaAlNP, GaAlNAs, GaAlPAs, GaInNP, GaInNAs, GaInPAs, InAlNP, InAlNAs, and InAlPAs. In another embodiment, fluorescent nanoparticles may include, for example, CuInS _2, CuInSe _2, CuGaS _2, CuGaSe _2, AgInS _2, AgInSe _2, AgGaS _2, and I-III- AgGaSe selected from the group consisting of ₂ VI2 chalcopyrite-type semiconductor quantum dots. In another embodiment, fluorescent nanoparticles may include, for example, LiAsSe _2, NaAsSe may be a IV-VI2 semiconductor quantum dots, such as those selected from the group consisting of ₂ and KAsSe _2. In yet another embodiment, the fluorescent nanoparticles may be IV-VI compound semiconductor nanocrystals such as, for example, SbTe. In a specific embodiment, the fluorescent nanoparticles are selected from the group consisting of InP, CuInS _2, CuInSe _2, CdTe, CdSe, CdSeTe, AgInS ₂ and AgInSe _2. In another embodiment, the fluorescent nanoparticles are selected from the above-mentioned materials with internal dopants such as, for example, ZnSe: Mn, ZnS: Mn, II-VI, III-V, I-III-V and IV -V group compound semiconductor nanocrystals. The dopant elements may be selected from Mn, Ag, Zn, Eu, S, P, Cu, Ce, Tb, Au, Pb, Tb, Sb, Sn and Tl. Here, the fluorescent nanoparticle-based fluorescent material may also include different kinds of QDs, for example, CdSe and ZnSe: Mn.

 It seems particularly advantageous to use II-VI quantum dots. Thus, in an embodiment, the semiconductor based fluorescent quantum dots may be selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, the more special is selected from the group consisting of HgZnSeTe and HgZnSTe are CdS, CdSe , CdSe / CdS, and CdSe / CdS / ZnS.

In an embodiment, Cd-free QDs are applied. In certain embodiments, the photoconversion nanoparticles include InP-based quantum dots such as III-V QDs, more particularly core-shell InP-ZnS QDs. The term "InP quantum dot" or "InP quantum dot" and similar terms may relate not only to "bare" InP QDs, but also to InP-ZnS QDs dot- , It may be related to core-shell InP QDs having a shell on an InP core such as core-shell InP-ZnS QDs,

Fluorescent nanoparticles (uncoated) can have dimensions in the 2-20 nm range, such as about 2-50 nm, especially 5-15 nm; In particular, at least 90% of the nanoparticles have dimensions in their respective indicated ranges (i.e., for example, at least 90% of the nanoparticles have dimensions in the range of 2-50 nm, or in particular at least 90% Have dimensions in the range of 5-15 nm). The term "dimensions" relates in particular to one or more of length, width, and diameter, depending on the shape of the nanoparticle.

 In embodiments, the photoconversion nanoparticles have an average particle size ranging from about 1 to about 1000 nanometers (nm), preferably from about 1 to about 100 nm. In an embodiment, the nanoparticles have an average particle size in the range of about 1-50 nm, especially 1 to about 20 nm, and generally at least 1.5 nm, such as at least 2 nm. In an embodiment, the nanoparticles have an average particle size in the range of about 1 to about 20 nm.

Typical dots are made of binary alloys such as cadmium selenide, cadmium sulphide, indium arsenide, and indium phosphide. However, the dots may also be made of ternary alloys such as cadmium selenide sulphide. These quantum dots have a diameter of 10 to 50 atoms and can contain only 100 to 100,000 atoms in the quantum dot volume. This corresponds to about 2 to 10 nanometers. For example, spherical particles such as CdSe, InP, or CuInSe ₂ with a diameter of about 3 nm may be provided. Fluorescent nanoparticles (uncoated) have a size in one dimension of less than 10 nm and can take the form of spheres, cubes, rods, wires, disks, multifods, and the like. For example, nanorods of CdSe with a length of 20 nm and a diameter of 4 nm can be provided.

Thus, in an embodiment, the semiconductor based fluorescent quantum dots include core shell quantum dots. In another embodiment, the semiconductor based fluorescent quantum dots include dots-in-rods nanoparticles. Combinations of different types of particles can also be applied. For example, core shell particles and toe-in rods can be applied and / or combinations of two or more of the nanoparticles described above, such as CdS and CdSe, can be applied. Here, the term "different classes" may relate to different types of semiconductor fluorescent material as well as different geometries. Therefore, a combination of two or more of the quantum dots (indicated above) or fluorescent nanoparticles may also be applied.

 In an embodiment, the nanoparticles may comprise semiconductor nanocrystals including a core comprising a first semiconductor material and a shell comprising a second semiconductor material, wherein the shell is disposed over at least a portion of the surface of the core. Semiconductor nanocrystals, including cores and shells, are also referred to as "core / shell" semiconductor nanocrystals.

 For example, the semiconductor nanocrystals may comprise a core having the formula MX, where M may be cadmium, zinc, magnesium, mercury, aluminum, gallium, indium, thallium, Sulfur, selenium, tellurium, nitrogen, phosphorus, arsenic, antimony, or mixtures thereof. Examples of materials suitable for use as semiconductor nanocrystal cores are ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, MgS, MgSe, GaAs, GaN, GaP, GaSe, GaSb, HgO, HgS, HgSe, HgTe Including the above-mentioned compounds, such as InAs, InN, InP, InSb, AlAs, AIN, AlP, AlSb, TIN, TIP, TlAs, TlSb, PbO, PbS, PbSe, PbTe, Ge, Si, Alloys comprising any of the foregoing, and / or mixtures comprising any of the foregoing.

 The shell may be a semiconductor material having a composition that is the same as or different from the composition of the core. Wherein the shell comprises an overcoat of a semiconductor material on the surface of the core semiconductor nanocrystals and wherein the shell comprises an overcoat of a semiconductor material on the surface of the core semiconductor nanocrystals and wherein the shell comprises a Group IV element, Alloys comprising any of the foregoing, including compounds, Group I-III-VI compounds, Group II-IV-VI compounds, Group II-IV-V compounds, ternary and quaternary compounds or alloys, and / RTI &gt; and / or mixtures comprising any of the foregoing. Examples are ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, MgS, MgSe, GaAs, GaN, GaP, GaSe, GaSb, HgO, HgS, HgSe, HgTe, InAs, InN, InP, InSb, AIN, AlP, AlSb, TIN, TIP, TlAs, TlSb, PbO, PbS, PbSe, PbTe, Ge, Si, alloys comprising any of the foregoing, and / or mixtures comprising any of the foregoing But are not limited to these. For example, ZnS, ZnSe or CdS overcoats can be grown on CdSe or CdTe semiconductor nanocrystals. An overcoating process is described, for example, in U.S. Pat. No. 6,322,901. By controlling the temperature of the reaction mixture during overcoating and monitoring the absorption spectrum of the core, an overcoated material having a high emission quantum efficiency and narrow size distribution can be obtained. The overcoat may comprise one or more layers. The overcoat may comprise at least one semiconductor material that is the same as or different from the composition of the core. Preferably, the overcoat has a thickness of from about 1 to about 10 monolayers. Overcoating can also have a thickness greater than ten monolayers. In embodiments, more than one overcoating may be included on the core.

 In particular, the overcoat comprises at least one semiconductor material that is different from the composition of the core; That is, it has a composition different from that of the core.

 In an embodiment, the surrounding "shell" material may have a band gap greater than the band gap of the core material. In certain other embodiments, the encapsulating shell material may have a bandgap that is smaller than the bandgap of the core material.

 In an embodiment, the shell may be selected to have atomic spacing that is close to the atomic spacing of the "core" substrate. In certain other embodiments, the shell and core materials may have the same crystal structure.

Examples of semiconductor nanocrystal (core) shell materials include, but are not limited to: red (e.g., (CdSe) ZnS (core) shell), green (e.g., (CdZnSe) CdZnS , Etc.), and blue (e.g., (CdS) CdZnS (core) shell) (see also above for examples of specific photoconversion nanoparticles based on semiconductors).

Therefore, the above-described outer surface can be the surface of a bare quantum dots (i.e., the QD does not include additional shells or coatings), or the core shell quantum dots (such as a core shell or dot in rod) The surface of the same coated quantum dots, i.e., the (outer) surface of the shell.

 Thus, in a particular embodiment, the photoconversion nanoparticles may be CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, GaN, GaP, GaAs, AlN, AlP, AlAs, InN, InP, And at least one of the cores and the shells including at least one of InAs, GaNP, GaNAs, GaPAs, AlNP, AlNAs, AlPAs, InNP, InNAs, InPAs, GaAlNP, GaAlNAs, GaAlPAs, GaInNP, GaInNAs, GaInPAs, InAlNP, InAlNAs, , Core shell nanoparticles.

Generally, the cores and shells comprise materials of the same grade, but are fundamentally composed of different materials such as a ZnS shell surrounding the CdSe core, et al.

In a particular embodiment, which may provide a relatively broad color gamut, the blue light source comprises a blue LED, the green light source comprises an LED having a center emission wavelength in the range of 510-540 nm, the first red light source comprises Mg , Ca, Sr, Ba) AlSiN 3: Eu ( in particular (Mg, Ca, Sr) AlSiN 3: Eu) and _{(Ba, Sr, Ca) 2} Si 5 - x Al x O x N 8 - x: Eu ( above X), and the second red light source comprises the second red phosphor comprising K ₂ SiF ₆ : Mn.

As shown above, the present invention provides an LCD display device comprising an illumination unit according to any one of the preceding aspects, configured as a backlight unit in another aspect. In another aspect, the present invention also provides a process for producing a green fluorescent material comprising a divalent europium-containing oxynitride, a divalent europium-containing thiogallate, a trivalent cerium-containing nitride, a trivalent cerium-containing oxynitride, (Mg, Ca, Sr, Ba) AlSiN ₃ : Eu and (Ba, Sr, Ca) ₂ Si _{5 - x} Al _x O _x N _{8 - x} : Eu And a second red phosphor selected from the group consisting of M ₂ AX ₆ doped with quadrivalent manganese, wherein M is selected from the group consisting of Li, Na, K, Rb, Cs, comprises a monovalent cation selected from the group consisting of NH _4, wherein a is Si, Ti, Ge, Sn, and 4 includes a cation selected from the group consisting of Zr, and where X Includes monovalent anions selected from the group consisting of F, Cl, Br and I, wherein at least F . However, as shown above, other combinations may also be envisaged.

As indicated above, the term "luminescent material" may also relate to a plurality of different fluorescent materials. In the present specification, the term fluorescent material relates specifically to inorganic fluorescent materials. Likewise, it also applies to the term "phosphor ". These terms are well known to those of ordinary skill in the art. Thus, combinations of phosphors can be applied, as is apparent to those of ordinary skill in the art. Optimization of the fluorescent substance (s) (or phosphors) for one or more of the constituent elements, activator concentration, particle size, etc., or optimization of the fluorescent substance combination (s) May be applied to optimize the illumination device.

The light source may be configured to (optical) chamber having a reflecting wall (s) (e. G. Being coated with a reflective substance such as TiO ₂₎ and the transparent window (window). In an embodiment, the window is a light conversion layer. In another embodiment, the window comprises a light conversion layer. This layer may be located upstream of the window or downstream of the window. In yet another embodiment, the light conversion layers are applied to both sides of the window.

 The terms "upstream" and "downstream" relate to the placement of items or features relative to the propagation of light from light generating means (here the light source), wherein, relative to the first position in the light beam from the light generating means, The second position in the light beam closer to the light generating means is "upstream ", and the third position in the light beam farther away from the light generating means is" downstream ".

The fluorescent material is configured to convert at least a part of the light source light. In other words, the light source can be said to be radiationally coupled to the fluorescent material. When the light source comprises a substantially UV-emitting light source, the fluorescent material may be configured to substantially convert all of the light source light impinging on the fluorescent material. When the light source is configured to generate blue light, the fluorescent material can partially convert the light source light. Depending on the configuration, some of the remaining light source light may be transmitted through the layer containing the fluorescent material.

The following are a plurality of applications of the present invention:

- Office lighting systems

- Home Application Systems

- shop lighting systems,

- Home lighting systems,

- accent lighting systems

Spot lighting systems,

- Theater lighting systems,

- Fiber application systems,

- projection systems,

- self lighting display systems,

Pixel-based display systems,

- segmented display systems,

- alarm signaling systems,

- medical lighting application systems,

- indicator signaling systems, and

- decorative lighting systems,

- Portable systems

- Automotive Applications

- Greenhouse lighting systems

As indicated above, the illumination unit can be used as a backlight unit in an LCD display device. Thus, in a further aspect, the present invention also provides an LCD display device comprising a lighting unit as defined herein, which is configured as a backlight unit.

The terms "violet light" or "violet emission" are particularly related to light having a wavelength in the range of about 380-440 nm. The terms "blue light" or "blue emission" are particularly relevant to light having wavelengths in the range of about 440-490 nm (including some purple and cyan hues). The term "green light" or "green emission" is particularly relevant to light having a wavelength in the range of about 490-560 nm. The terms "yellow light" or "yellow emission" are associated with light having a wavelength in the range of about 540-570 nm. The terms "orange light" or "orange emission" are particularly relevant to light having a wavelength in the range of about 570-600 nm. The terms "red light" or "red emission" are particularly relevant to light having a wavelength in the range of about 600-750 nm. The terms "pink light" or "pink emission" refer to light having blue and red components. The term "visible", "visible light" or "visible emission" refers to light having a wavelength in the range of about 380-750 nm.

 The term "substantially" herein, such as in "substantially all emissions" or "consisting substantially of" The term "substantially" will also include "entirely "," completely ", "all" Thus, in the embodiments, the adjective may also be substantially removed. If applicable, the term "substantially" may also be associated with at least 90%, such as at least 95%, especially at least 99%, more particularly at least 99.5% including 100%. The term " comprise "also includes embodiments in which the term " comprise " means" consist of ".

 Furthermore, in the description and in the claims, the terms first, second, third, etc. are used to distinguish similar elements and are not intended to be necessarily sequential or chronological order. It should be understood that the terms so used are interchangeable in appropriate circumstances and that the embodiments of the invention described herein may operate with sequences other than those described or illustrated herein.

The devices herein are among other things described during operation. As will be apparent to those of ordinary skill in the art, the present invention is not limited to devices during operation or operation.

 It should be noted that the above-described embodiments illustrate rather than limit the invention, and that ordinary persons skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprises" and its utility does not exclude the presence of elements or steps other than those listed in the claims. An article before an element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in different dependent claims does not indicate that a combination of these measures can not be used to advantage.

The invention also applies to an apparatus comprising at least one of the characterizing features described in the description and / or shown in the accompanying drawings. The invention also relates to a method or a process comprising at least one of the characterizing features illustrated in the description and / or illustrated in the accompanying drawings.

The various aspects discussed in this patent may be combined to provide additional advantages. In addition, some of the features may form the basis for one or more split applications.

Reference will now be made, by way of example only, to embodiments of the invention, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:
Figures 1a-1e schematically depict some aspects of the present invention; These drawings are not necessarily scaled;
2A shows a silicon substrate layer containing K ₂ SiF ₆ : Mn powder (R1, E1), ECAS powder (R2, E2) and 18 vol.% K ₂ SiF ₆ : Mn and 2 vol.% ECAS Reflection and emission spectrum. Figure 2b shows the emission spectrum (E4) of the silicon substrate layer and blue LED (B) containing 18 vol.% K ₂ SiF ₆ : Mn and 2 vol.% ECAS. The narrow band fluorescent material includes at least one emission line having a central wavelength CW and FWHM in excess of 610 nm.
3: Transmission functions selected for the RGB pixels of the LCD display.
4a-4b: shows a chromaticity chart (CIE chromaticity diagram) on the left side with a 510 nm green LED and (b) an emission spectrum of the backlight unit on the right side;
5a-5b: shows a chromaticity chart (CIE chromaticity diagram) on the left side and (a) emission spectrum of the backlight unit on the right side with a 520 nm green LED;
6a-6b: shows a chromaticity chart (CIE chromaticity diagram) on the left side and (a) emission spectrum of the backlight unit on the right side, with a 530 nm green LED; And
7a-7b shows a chromaticity chart (CIE chromaticity diagram) on the left side and a emission spectrum of the backlight unit on the right side, with a 540 nm green LED.

FIG. 1A schematically depicts an embodiment of a lighting unit 100 as described herein. The illumination unit 100 is configured to include a light source 110 that is a blue light source 110 (i.e., a light source 110 of blue light, a reference numeral 110 denotes a light source, (Red light) source 1310 (first red light source) including a first red fluorescent material 1311, configured to provide a red light 31 having a broadband spectral light distribution, a light source 120 ) And a second (red light) light source 1320 comprising a second red fluorescent material 1321, configured to provide red light 32 having a spectral light distribution comprising one or more red emission lines do.

Here, in this embodiment, the light source 110 of blue light includes a blue LED. An optical converter 1300 may be disposed on this light source 110 of blue light, such as in a resin on an LED die, The optical converter 1300 may include one or more fluorescent materials. Here, the optical converter 1300 includes both the first red fluorescent material 1311 and the second red fluorescent material 1321. These two fluorescent materials are red light sources because they can absorb the light source light of the blue light source 110 and convert it into the broadband red light 31 and the narrow band red light 32. Blue light is denoted by reference numeral 11; Its light source is denoted by reference numeral 110.

By way of example, the light source 120 of green light in this embodiment is shown as an LED configured to generate green light, This can therefore be LED without the fluorescent material.

Here, the illumination unit includes an optical chamber 105 having a light transmissive window 102. Light from the light sources exits the window 102, that is, broadband red light 31, narrowband red light 32, green light 21, and blue light 11. All light exiting the light exit window or transmissive window 102 is displayed as illumination unit light 101. As shown above, this light consists of components, which combine with a set of RGB filters to generate a front of screen (FOS) wide color gamut. The color regions are individually defined as color points due to the selective transmission of light from the light source for all color filters.

The blue light source 110 in combination with the two red phosphors 1311 and 1321 is also referred to herein as a "pc-pink LED" (which can therefore provide pink light, which in this embodiment is blue light 11, The red light 31, and the narrow band red light 32).

1B schematically depicts an embodiment in which the light source 110 of blue light is an LED (the light source 107 includes a light source 110 configured to provide blue light). This LED is used to provide blue light to the fluorescent materials provided as an upstream layer or coating to reach the light transmitting window 102. Thus, in this embodiment, the transducer 1300 is disposed at a non-zero distance from the LED die 111. This distance is denoted by d1 (see further below). The converter 1300 may be disposed at a non-zero distance d1 from a light source 110 (or other light source (s) that may be, for example, a light emitting diode) Or may be zero when embedded in a (silicon) cone of LEDs (see also Fig. 1c). The converter 1300 may optionally allow at least a portion of the light source light 11 to pass through the transducer. In this way, downstream of the transducer, a combination of transducer light based on the luminescence (s) of the fluorescent material included in the transducer 1300, and the light source light 11 can be found. The light downstream of the light converter is indicated by the illumination unit light 101. The distance d1 may in particular be in the range of 0.1-100 mm, especially at 0.5-100 mm, such as 1-20 mm, especially at applications 1-3 and 5-50 Lt; RTI ID = 0.0 > mm. &Lt; / RTI &gt; However, it should be noted that the present invention is not limited to applications where d1 &gt; 0. The present invention, and the specific embodiments described herein, may also be applied to other embodiments having dl = 0. In such cases, the optical transducer may be configured in physical contact, particularly with the LED die.

It is noted that the light source 107 may alternatively be a light source configured to provide UV light. In such a case, the illumination unit 100 may be configured to prevent (substantially) the light source light from going downstream of the light exit window / transducer. For example, the optical transducer may be configured to convert substantially all of the UV light source light into fluorescent light of one or more fluorescent materials that the optical transducer comprises. In this embodiment, the light source 120 (of green light) comprises a green fluorescent material denoted by reference 1200. This green fluorescent material 1200 provides green light 21 when excited. The optical converter 1300 may further include a blue fluorescent material configured to generate blue light upon excitation by the light source light 11. [

Alternatively or additionally, the blue light source 110 includes a UV LED with a blue phosphor that at least partially converts the UV light source to blue light.

Fig. 1c schematically depicts an embodiment in which a light transducer 1300 is disposed on an LED die 111 of a light source 107. Fig. This light source 107 may be a UV LED, or it may be a blue light source 110, i. E. A blue LED, as depicted. The converter 1300 in such an embodiment includes a broadband red fluorescent material 1311; Thereby providing a first red light source 1310 (note that this reference designates a light source that is a red light source). In addition, the converter 1300 includes a narrow band red fluorescent material 1321. In this manner, a second red light 1320 is provided; The second (red) light source 1320 (i.e., the second red light source 1320) includes narrow band fluorescent material 1321, which provides narrow band red light 32 when excited. Here, the converter 1300 also optionally includes a green fluorescent material 1200 which, when excited, provides green light 21 (and thereby also becomes a green light source 120).

It should be noted that the above-described embodiments may be combined. Also, as will be apparent to those of ordinary skill in the art, the present invention also relates to alternative arrangements.

1d schematically depicts one of the applications of the illumination unit 100 in the liquid crystal display device 2, wherein the liquid crystal display device comprises one or more illumination units 100 (here, one illumination unit is a schematic (Not shown), as well as an LCD panel 300 that can be backlighted with the illumination device light 101 of the illumination unit (s) 100 of the backlight unit 200. Again, by way of example, light source (s) 107 are blue light sources 110. In this embodiment, a plurality of such light sources 110 are depicted, which are used to excite the fluorescent material (s) included in the converter 1300. Such an LCD display device may further include one or more color filters, particularly disposed downstream of the backlight unit (but upstream of the display of the LCD display device). These filters can filter the (white) light device 101. For the sake of clarity, these filters are not depicted.

Figure 1e schematically depicts the emission spectrum of a broadband fluorescent material. The FWHM line indicates the middle between the top of the band and the background signal; CW denotes a wavelength at which the intensities equivalent to the left and right of the dotted line at the wavelength are found. This is known as the central wavelength.

Examples

Example 1

Above all, a red-emitting phosphor layer necessary for the pc- pink LED described herein _{ECAS (Sr 0 8 Ca 0 2} SiAlN 3...: Eu (0.8%)) commercially available in the silicon base polymer at room temperature and K ₂ SiF ₆ : Mn (Applied Physics Journal 104, 023512, 2008, Direct synthesis of K ₂ SiF ₆ : Mn ^{4 +} phosphors by wet chemical etching of Si wafers and properties, prepared as reported by Adachi et al.) For example, by suspending. There is a well mixed slurry and is tape cast on a glass substrate and cured at 150 캜 for 4 hours in air. The cured layers have a thickness of about 120 탆, and the charging grade of the phosphor is 20 vol.% (18 vol.% K ₂ SiF ₆ : Mn, 2 vol% ECAS). The measured reflection spectra of the silicon substrate layer containing K ₂ SiF ₆ : Mn and ECAS powder and 18 vol% K ₂ SiF ₆ : Mn and 2 vol% ECAS are shown in FIG. The emission spectrum of the layer comprising the comparative K ₂ SiF ₆ : Mn and ECAS is shown in FIG. 2b.

Figure 2a shows a graphical representation of the results of an experiment using a K ₂ SiF ₆ : Mn powder (R1 (ie, reflection); E1 (ie, release)), ECAS powder (R2; E2) and 18 vol.% K ₂ SiF ₆ : And the reflection and emission spectrum of the silicon base layer (R3) including the silicon base layer (R3). Figure 2b shows the emission spectrum (E4) of the silicon substrate layer and blue LED (B) containing 18 vol.% K ₂ SiF ₆ : Mn and 2 vol.% ECAS. Narrowband fluorescent materials include at least one emission line with a narrow central FWHM of well below 610 nm and also below the displayed central wavelength CW and 50 nm.

A large color space located within the NTSC can be obtained by an additional green LED centered at 530 nm.

Thus, the present invention is a phosphor-converted LED with a narrow deep red emission component as MnIV doped K ₂ SiF ₆ in combination with a narrow green emission component having an FWHM ≤ 50nm In an embodiment, NTSC and sRGB defined (definitions) While another phosphor is added to the MnIV component to maximize color gamut coverage. The light source may therefore consist of:

A: Direct emission green LED with peak emission wavelength > 510nm and < 540nm, and two phosphors - one MnIV doped, the second phosphor with peak emission between 590 and 630nm and FWHM &gt; With pc-LED.

B: a green phosphor of? -SiAlON or (Sr, Ca) _(1-x) Ga ₂ S ₄ : Eu _x doped with Eu (0.01 <x <0.1), an MnIV doped phosphor and a phosphor of between 590 and 630 nm Three phosphors pcLED with peak emission and third phosphor with FWHM ≥ 70 nm.

LCD backlight Phosphor - converted red Phosphorescent  Additional examples of application.

The following example illustrates a set of RGB color filters, shown in FIG. 3, associated with the spectral composition of the LED backlight unit when R represents a red filter, G represents a green filter, and B represents a blue filter Shows the FOS performance for an LCD display with a display.

First, some reference examples are given: Typical pcLED backlight units combine a blue emitting LED with a green emitting and a red emitting phosphor.

Reference Example 1

Green _{phosphor: LuAG (Lu 2 94 Al 5} O 12:. Ce 0 .06)

Red phosphor: Eu doped (Sr, Ca) AlSiN ₃

The FOS color gamut, compared to the sRGB and NTSC defined color gamut, along with the color points of the backlight unit and the white FOS color point and the emission spectrum of the backlight unit, is shown for blue LEDs with peak emission at 440, 450, 460 and 470 nm respectively , Was determined:

Here pr_redbroad, pr_green, pr_blue, pr_redKSiF (see below) and pr_redQD (see below) are power fractions for different emitters. These values add up to 100%.

Reference Example 2

To increase the NTSC color reverse coverage, the pink emitting LED (blue LED + red phosphor) is combined with the green emitting LED in the 520 - 530 nm peak emitting range.

Green: Direct emitting LED

Red phosphor: Eu doped (Sr, Ca) AlSiN ₃

Blue LED: 450 nm peak emission

The following data were obtained:

Compared with the pcLED green backlight unit,

The color intensity LE does not increase significantly.

Reference Example 3

Due to the limited cut-off of the red filter, the NTSC color reverse coverage can only be increased to a considerable extent if a narrow red emitting phosphor is used.

Known materials with desired properties are MnIV doped fluoride phosphors:

Green: Direct emitting LED

Red phosphor: MnIV doped K2SiF6

Blue LED: 450 nm peak emission

Now the color station approaches the NTSC definition area, but it does not cover the same color space. A deficit is a point that is too red and causes problems in image color reproduction.

In addition, the FOS colorimetry by the backlight units using different direct green emitting LEDs at 510, 520, 530, and 540 nm peaks was determined.

Example 2

The object of the present invention is, above all, to construct an LCD backlight unit with maximum overlap of the FOS color space with the NTSC definition.

This is done by combining a direct green emitting LED with a blue LED and a pcLED consisting of two phosphors-one Mn (IV) doped phosphor and the other Eu-doped (Sr, Ca) AlSiN3

Figures 4A-B show the FOS color gamut compared to sRGB and NTSC defined color regions with backlight emissions.

Figures 4a-4b show a chromaticity chart (CIE chromaticity diagram) on the left side with a 510 nm green LED and an emission spectrum of the backlight unit on the right side (b).

5a-5b: shows a chromaticity chart (CIE chromaticity diagram) on the left side and (a) emission spectrum of the backlight unit on the right side with a 520 nm green LED.

6A-6B: shows a chromaticity chart (CIE chromaticity diagram) on the left side and a emission spectrum of the backlight unit on the right side, with a 530 nm green LED.

7a-7b shows a chromaticity chart (CIE chromaticity diagram) on the left side and a emission spectrum of the backlight unit on the right side, with a 540 nm green LED.

The lighting unit according to the invention appears to give a very good overlap with the NTSC color space as well as an NTSC value that is greater than 5% higher than all the reference examples.

In summary, the following results were obtained.

Reference Example 4

The following combinations were evaluated:

Green: Direct-emitting LED

Red phosphor: Quantum dot phosphor with peak emission at 630 nm

Blue LED: 460 nm peak emission

The FOS color gamut with backlight units using different direct green emission LEDs at 510, 520, 530, and 540 nm peaks, respectively, was evaluated. In the following table the area of the FOS luma equivalent for the green LEDs and the 450 nm blue LED for the sRGB and NTSC definitions is shown.

Example 3

In addition, combinations according to the invention were evaluated:

Green: Direct emitting LED

Red phosphor: Qdot + red CASN phosphor with peak emission at 630 nm, peak emission 620 nm

Blue LED: 460 nm peak emission

The FOS color gamut with backlight units using different direct green emission LEDs at 510, 520, 530, and 540 nm peaks, respectively, was evaluated. In the following table the area of the FOS luma equivalent for the green LEDs and the 450 nm blue LED for the sRGB and NTSC definitions is shown.

It also appears here that the lighting unit according to the invention gives a very good superposition with the NTSC color space as well as an NTSC value higher than 5% than all the reference examples.

Claims (15)

As illumination unit (100):
The blue light source 110,
The green light source 120,
A first red light source 1310 comprising a first red luminescent material configured to provide red light 31 having a broadband spectral light distribution, and
A second red light source 1320 comprising a second red fluorescent material configured to provide red light 32 having a spectral light distribution comprising one or more red emission lines,
(100). The method of claim 1, wherein the first red light source (1310) provides a red light (31) having a broadband spectral light distribution having a center emission wavelength? 590 nm and having a full width half maximum (FWHM) (100). The method according to any one of claims 1 to 7, wherein the first red light source (1310) comprises a first red fluorescent material selected from the group consisting of a divalent europium-containing sulfide, a divalent europium-containing nitride, (100). 4. The phosphor according to any one of claims 1 to 3, wherein the first red light source (1310) comprises (Ba, Sr, Ba) AlSiN ₃ : Eu and x = ) ₂ Si _{5 - x} Al _x O _x N _{8 - x} : Eu. The method of any one of claims 1 to 4, wherein the second red light source (1320) has a spectral light distribution comprising one or more red emission lines having a center emission wavelength? 610 nm, and further comprising a FWHM And red light (32) having one or more red emission lines. The method of any one of claims 1 to 5, wherein the second red light source (1320) comprises the second red phosphor selected from the group consisting of M ₂ AX ₆ doped with quadrivalent manganese, wherein M 4 is one selected from the group consisting of Li, Na, K, Rb, Cs, NH _4, which comprise a cation and wherein a is selected from the group consisting of Si, Ti, Ge, Sn, and Zr Wherein X comprises a monovalent anion selected from the group consisting of F, Cl, Br and I, but comprises at least F. Article according to any one of the preceding claims, wherein the second red light source 1320 K ₂ SiF _6: a lighting unit (100) that includes the second red fluorescent material containing Mn. 8. A lighting unit (100) according to any one of claims 1 to 7, wherein the second red light source (1320) comprises the second red fluorescent material comprising a photoconductive nanoparticle material. 9. The illumination unit (100) of any one of claims 1 to 8, wherein the blue light source (110) comprises a blue light emitting diode (LED). 10. A device according to any one of claims 1 to 9, wherein the green light source (120) comprises a fluorescent material configured to convert at least a portion of the blue light of the blue light source and to convert the blue light into green light Illumination unit (100). A green light source (120) according to any one of claims 1 to 10, wherein the green light source (120) comprises a fluorescent material comprising M ₃ A ₅ O ₁₂ : Ce ³⁺ , wherein M is at least one of Sc, Y, Tb, Gd And Lu, wherein A is selected from the group consisting of Al and Ga. 12. Illumination unit (100) as claimed in any one of claims 1 to 11, wherein the green light source (120) comprises an LED having a center emission wavelength in the range of 510 - 540 nm. 13. A method according to any one of claims 1 to 12, wherein the blue light source (110) comprises a blue light emitting diode (LED) and the green light source (120) including the LED, and the first red light source 1310 (Mg, Ca, Sr, Ba ) AlSiN 3: Eu and (x = 0-4 having a) (Ba, Sr, Ca) 2 Si 5 - x Al _x O _x N _{8 - x} : Eu, and the second red light source 1320 comprises the second red fluorescent material containing K ₂ SiF ₆ : Mn (100). An LCD display device (2) comprising the illumination unit (100) according to any one of claims 1 to 13 configured as a backlight unit. As a combination of phosphors:
(1) a green fluorescent substance selected from the group consisting of divalent europium-containing oxynitrides, divalent europium-containing thiogallates, trivalent cerium-containing nitrides, trivalent cerium-containing oxynitrides, and trivalent cerium-
(Mg, Ca, Sr, Ba) AlSiN ₃ : Eu and (Ba, Sr, Ca) ₂ Si _{5 - x} Al _x O _x N _{8 - x} : Eu A first red fluorescent material selected from the group consisting of
(3) a second red fluorescent material selected from the group consisting of M ₂ AX ₆ doped with tetravalent manganese
/ RTI &gt;
Wherein M 4 is one selected from the group consisting of Li, Na, K, Rb, Cs, NH _4, which comprises a cation, wherein A is selected from the group consisting of Si, Ti, Ge, Sn, and Zr Wherein X comprises a monovalent anion selected from the group consisting of F, Cl, Br and I,
Combinations of phosphors.

Images